[vector_graphics_compiler] fix-null-exception (#8006)

The following SVG throw an exception (when using flutter_svg) : https://sweden.a.bigcontent.io/v1/static/10000199.

This SVG contain an empty tag : <polygon xmlns="http://www.w3.org/2000/svg" fill="#0a287d" points="" id="polygon7"/> which lead to the issue.

This PR check if path is null to avoid the issue.

PR from dnfield/vector_graphics#254

Author: EArminjon

packages/vector_graphics_compiler/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.1.15
+
+* Fixes a bug where empty tags caused the parser to crash.
+
 ## 1.1.14
 
 * Makes the package WASM compatible.

packages/vector_graphics_compiler/lib/src/svg/parser.dart

@@ -895,7 +895,10 @@ class SvgParser {
       return false;
     }
     final ParentNode parent = _parentDrawables.last.drawable;
-    final Path path = pathFunc(this)!;
+    final Path? path = pathFunc(this);
+    if (path == null) {
+      return false;
+    }
     final PathNode drawable = PathNode(path, _currentAttributes);
     checkForIri(drawable);
 

packages/vector_graphics_compiler/pubspec.yaml

@@ -2,7 +2,7 @@ name: vector_graphics_compiler
 description: A compiler to convert SVGs to the binary format used by `package:vector_graphics`.
 repository: https://github.com/flutter/packages/tree/main/packages/vector_graphics_compiler
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+vector_graphics%22
-version: 1.1.14
+version: 1.1.15
 
 executables:
   vector_graphics_compiler:

packages/vector_graphics_compiler/test/parser_test.dart

@@ -7,6 +7,7 @@ import 'dart:io';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:vector_graphics_compiler/src/svg/numbers.dart';
 import 'package:vector_graphics_compiler/vector_graphics_compiler.dart';
+
 import 'test_svg_strings.dart';
 
 void main() {
@@ -1948,6 +1949,19 @@ void main() {
       ],
     );
   });
+
+  test('Parse empty tag', () {
+    const String svgStr = '''
+     <svg xmlns="http://www.w3.org/2000/svg" width="200" height="200" viewBox="0 0 200 200">
+        <polygon
+            fill="#0a287d"
+            points=""
+            id="triangle"/>
+     </svg>
+    ''';
+
+    expect(parseWithoutOptimizers(svgStr), isA<VectorInstructions>());
+  });
 }
 
 const List<Paint> ghostScriptTigerPaints = <Paint>[